Geoscience Reference
In-Depth Information
EARTH'S INTERNAL
STRUCTURE, ROCK CYCLE,
AND GEOLOGIC TIME
C H A P T E R T W E L V E
The previous chapter discussed the formation and character of soils, which can be viewed as the Earth's skin.
Now it is time to look more intently at the solid Earth by focusing on its internal structure and composition. The
inner Earth is important to understand because processes far below the surface drive the movements of our
planet's outermost layer, the crust. Geographers are interested in the composition of the crust because it is the
part of the solid Earth that most directly affects people, such as when an earthquake devastates a community. This
chapter will also give you an appreciation for geologic time and why it is relevant, especially when you consider
how quickly Earth is now changing due to human impacts.
